(a) Field of the Invention
The present invention relates to a transmission apparatus of a hybrid vehicle and more particularly, the present invention relates to a transmission apparatus of a hybrid vehicle that includes a safety unit to prevent rotation of a two-way clutch in a particular direction when an engine of the hybrid vehicle is driven.
(b) Description of the Related Art
Generally, a hybrid vehicle is a vehicle that is driven by efficiently combining two or more different types of power sources. The hybrid vehicle generally uses an engine and a motor/generator as power sources. The hybrid vehicle uses the motor/generator having relatively excellent low speed torque characteristics as a main power source at a low speed and uses the engine having relatively excellent high speed torque characteristics as a main power source at a high speed. Therefore, since the hybrid vehicle terminates an operation of the engine using fossil fuel and uses the motor/generator in a low speed section, fuel efficiency is improved and exhaust gas is reduced.
The hybrid vehicle as described above includes a first motor/generator, a second motor/generator, and a clutch. The first motor/generator is configured to perform a starting or power-generating function of the engine, and the second motor/generator is configured to drive or brake the hybrid vehicle. In addition, the clutch may be configured in a one-way clutch type to selectively connect or disconnect driving elements of the motor and driven elements of vehicle wheels to or from each other. For example, the clutch and the engine are disconnected in an electronic vehicle (EV) mode in which the hybrid vehicle is driven by a driving torque of the motor, and are connected in a hybrid electronic vehicle (HEV) mode in which the hybrid vehicle is driven by driving torques of the motor and the engine.
In the one-way clutch type, there is a limitation that the second motor/generator is operated only in the state in which it rotates in a forward direction, that is, when the vehicle moves forward. Therefore, research into a two-way clutch type in which the second motor/generator may rotate in a reverse direction even when the vehicle moves rearward has been conducted. However, when applying the two-way clutch to the hybrid vehicle and a lever of the two-way clutch moves to a specific direction (e.g., a reverse (R) stage) during a period in which the engine is driven due to an error in a control or an inexperienced manipulation, a torque of the engine may be applied in a direction in which a carrier is locked. Therefore, the two-way clutch may be damaged or the engine may be stopped.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.